document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=808810>Question 808810</A>: <I><SPAN STYLE=\"word-break: break-all;\"> do a proof for the following arguments:\r<BR>\n" );
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document.write( "1. XvY<BR>\n" );
document.write( "2. ~F<BR>\n" );
document.write( "3. D > X<BR>\n" );
document.write( "4. ~Y&F     /~D&F (conclusion)\r<BR>\n" );
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document.write( "1.x > ~D<BR>\n" );
document.write( "2. XvC<BR>\n" );
document.write( "3. C>F<BR>\n" );
document.write( "4. KvP<BR>\n" );
document.write( "5. ~D>B     / (BvF)vD (conclusion)\r<BR>\n" );
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document.write( ">= horshoe<BR>\n" );
document.write( "v= wedge<BR>\n" );
document.write( "~tilde </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #487194 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=487194\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "In the first one, it is not possible to conclude Not D And F because you are given that Not F is true, hence F is false, hence F And anything else is False.\r<BR>\n" );
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document.write( "For the second one, assume  Not F, then from C => F, you get Not C by modus tollens.  Not C together with X or C gives you X.  X => Not D, and then Not D => B.  B true makes B or F or D true.  Assume Not D, then Not D => B, and B or F or D is true.  Finally, assume Not B.  Not B together with Not D => B gives you D by modus tollens, and D means B or F or D is true\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi}\ +\ 1\ =\ 0\"><BR>\n" );
document.write( "<font face=\"Math1\" size=\"+2\">Egw to Beta kai to Sigma</font><BR>\n" );
document.write( "My calculator said it, I believe it, that settles it<BR>\n" );
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